2. Redheads have a higher tolerance for certain types of pain. The same gene mutation is responsible for both phenomena

3. Eye sight is more important than reaction time when it comes to hitting a fastball

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The human eye can't physically track an MLB fastball in the hitting zone and tell the muscles where to move.

Instead our brains recognize the ball as it leaves the pitcher's hand and predicts where the ball will go based on visual information. Eye sight is the most important genetic aspect of hitting, and 58% of MLB players have "superior" depth perception compared to 18% of nonathletes.

Albert Pujols is only in the 66th percentile of reaction time compared to college students.

6. Not all Kenyans are good distance runners. Descendants of the Kalenjin (a tribe in Kenya's Rift Valley) make up 12% of the population but account for the vast majority of the country's distance runners

7. The Kalenjin (Kenyans) are genetically made for distance running because they have proportionally long legs, light limbs, and have evolved larger lungs from living at high altitude for centuries

8. 17% of Americans between ages 20 and 40 who are over 7-feet tall play in the NBA

9. The Jamaican sprinting phenomenon is the perfect example of nature and nurture working together

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There are genetic factors that contribute to Jamaicans being the world's best short distance runners. They typically have long limbs and narrow hips, and nearly all of them have the ACTN3 "sprint gene" variant.

But there's also an environmental factor — it's nearly impossible to be a talented sprinter in Jamaica and not get 1) discovered, 2) funneled into track instead of other sports.

Usain Bolt wanted to play cricket or soccer. If he grew up anywhere else on Earth he wouldn't have been a sprinter.

10. Sudan is a sleeping giant in distance running

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The Kalenjin gene pool that accounts for most of the champion Kenyan distance runners also exists in southern Sudan.

But unlike Kenya, Sudan has a lack of stability and infrastructure that has so far prevented a running system or culture from ever developing. Theoretically though, it's likely to be a hot bed of potential marathoners.

13. The odds of being a genetically perfect endurance runner are 1 in a quadrillion

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Scientists identified 23 different gene variants that make someone a better natural endurance runner. When they ran the odds that a human would have all 23 variants, they found the odds were 1 in 1 quadrillion.

14. Your ability to get better with practice is genetic

Donald Thomas won the high jump world championships after 8 months of trianing
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Scientists have found that practice isn't created equally for everyone.

Different people can do the same exercises for the same amount of time and their improvement over time will be totally different. For instance some people's aerobic capacity won't get better even with deliberate training.

That's part of the reason why it will take some people 3,000 hours of practice to achieve mastery, and others 10,000.